1. Field of the Invention
The present invention relates to an error correction coding method and apparatus, and more particularly, to a threefold error correction coding method and apparatus for reinforcing an error correction capability of a system which uses an inner error correction code and an outer error correction code with respect to data compressed at a high compression rate.
2. Description of the Related Art
A high definition digital video cassette recorder (HD-DVCR) is a system using an inner error correction code and an outer error correction code for channel coding. The HD-DVCR can record or reproduce signals adopting an A-TV (Advanced Television) system of U.S.A. The HD-DVCR is used as a data storage in which data compressed according to the MPEG II standard can be stored and from which the stored data is reproduced. The HD-DVCR uses the same recording format and channel processing portion as those of SD-DVC (standard digital video camcorder). For example, for 525/60 system, the HID-DVCR uses 10 segment recording formats in which one-frame data is recorded on 10 tracks, and uses an inner error correction code and an outer error correction code for error-correcting the compressed data.
However, since the HD-DVCR uses variable length coding according to the MPEG II standard, it provides a higher compression rate than the SD-DVC which provides a compression rate of 1/5 or so. Therefore, when the HD-DVCR and the SD-DVC use the same error correction techniques, the HD-DVCR provides a lower quality of picture than the SD-DVC, in accordance with an error degree in a transmission channel. That is, even though the SD-DVC provides an excellent quality of picture, the HD-DVCR causes severe degradation in the quality of picture and makes picture restoration impossible.
To solve the above problems, it is an object of the present invention to provide an error correction method for reinforcing an error correction capability, by using an additional error correction code in addition to an inner error correction code and an outer error correction code.
It is another object of the present invention to provide an apparatus embodying the above threefold error correction method.
To accomplish the above object of the present invention, there is provided an error correction method for use in a recording/reproducing apparatus for dispersedly recording one-frame data on a plurality of tracks, the error correction method comprising the steps of: (a) format converting received digital data into sync blocks each of which has a predetermined size; (b) interleaving data of the sync blocks which are allocated on different tracks in each frame using the sync blocks stored in step (a) and performing error correction coding with respect to the interleaved data; and (c) performing inner error correction coding and outer error correction coding with respect to the error correction coded data.
To accomplish the other object of the present invention, there is provided a recording/reproducing apparatus for dispersedly recording one-frame data on a plurality of tracks, the recording/reproducing apparatus comprising: a trans-codec for format converting received digital data into sync blocks each of which has a predetermined size, and converting the sync blocks into a format possessed by the received digital data;
error correction means for interleaving data of the sync blocks allocated on different tracks in each frame using the sync blocks supplied from the trans-codec and performing frame error correction coding with respect to the interleaved data, and for error correction decoding and deinterleaving the frame error correction coded data;
an error correction codec for performing inner code/outer code error correction coding with respect to the frame error correction coded data and performing inner code/outer code error correction decoding with respect to the inner code/outer code error correction coded data; and
a recording/reproduction unit for recording the data supplied from the error correction codec on a recording medium and supplying the data recorded on the recording medium to the error correction codec.